Maximizing grip is typically the goal of a tire engineer, but rubber friction is notoriously difficult to predict. Hysteretic friction models can estimate friction using complex modulus and power spectral density (PSD), but they rely on assumptions that do not hold for asphalt–rubber interactions. A method is here presented to model rubber interactions with more realistic surfaces directly, overcoming many of these limitations. The presentation also demonstrates how representative asphalt surfaces differ in contact behavior and how the model can be used to predict contact area, friction and heating through the tread.

• Why power spectral density is not enough to describe asphalt roughness
• How to generate surfaces with more representative roughness
• How the Boussinesq solution can be used to model the interaction between viscoelastic materials and any topography
• The differences in contact behavior between different asphalt surfaces and why Persson's model typically underpredicts the real area of contact
• How the model can be extended to evaluate the resulting heating through the tread from viscous energy loss